Re: [PATCH 0/4] Add tooling to disable debugfs on OMAP based systems

[Richard Weinberger <richard@nod.at>]

----- Ursprüngliche Mail -----
> Von: "Andreas Kemnade" <andreas@kemnade.info>
> it is usually not about individual registers, but about accessing
> unpowered devices/modules,
> 
> so it is probably more the logic like:
> 
> if (pm_runtime_is_suspended(regmap->device))
>	-EACCESS;
> 
> Try to play around with on >power/control in sysfs.

Well the that regmap is owned by the syscon mfd.
And in case of CTRL_MODULE_CORE only accessing some reserved registers causes
an abort.

For registers like dsp_system@40d00000 it's maybe indeed due to an unpowered module.
I'll double check that.
 
>> So, add tooling to allow disabling debugfs access to such dangerous registers.
>> Splitting the register map definitions in the device tree seemed less practical
>> to
>> me since it would unnecessarily make the device trees more complicated.
>> 
> So is it really a description of the hardware? Maybe there are some special
> cases, too.

IMHO, "There are problematic registers, don't blindly mess with them" is a description of the hardware.

Thanks,
//richard